Device for adjusting position of light source for projectors and the like

ABSTRACT

A device is provided for precisely positioning a light source in the optical system of a projector or the like, especially relative to a condenser system and a reflecting mirror. It consists of two position adjustment members, one being adjustable along two coordinate axes and the other being adjustable along the third coordinate axis. It is extremely compact in size, especially in thickness and is well adapted for miniaturization of a projector or the like. It is also very simple in operation to attain a highly uniform field with high luminance.

United States Patent Fujimoto DEVICE FOR ADJUSTING POSITION OF LIGHTSOURCE FOR PROJECTORS inventor:

Assignee:

Filed:

App]. No

AND THE LIKE Sakae Fniimoto, Tokyo, Japan Ricoh Co., Ltd., Tokyo, JapanNov. 10, 1970 Foreign Application Priority Data Nov. l2,

U.S. CL...

1969 Japan ..44/ 107399 Int. Cl. ..F2lv 19/02 Field of Search ..240/44,44.2, 41.6; 353/87;

References Cited UNITED STATES PATENTS Arbuckle ..240/44.2

[ Oct. 24, 1972 Woliensak et a]. ...24o/44.2 x Godley ..240/44.2

Primary ExaminerSamuel S. Matthews Assistant Examiner-Richard M. SheerAttorney-Henry T. Burke, RobertScobey, Robert S. Dunham, P. E.Henninger, Lester W. Clark, Gerald W. Griffin, Thomas F. Moran, R.Bradlee Boa], Christopher C. Dunham and John F. Scully 7] ABSTRACT 2Claims, 2 Drawing Figures |2- :2 l W H M S mLUJ T W 2 4 3 8 l3 I9 6d 602o \4 6G 5 l8 l8 7 DEVICE FOR ADJUSTING POSITION OF LIGHT SOURCE FORPROJECTORS AND THE LIKE BACKGROUND OF THE INVENTION:

The present invention relates to generally a projector and the like andmore particularly a device for adjusting the position of a light sourcefor projectors and the like. The device is capable of three-dimensionaladjustment of the position of the light source and is extremely compactin size, especially in thickness.

When a highly uniform field with high luminance is required by, forinstance, an overhead projector, the position of a filament of a lightsource relative to a reflecting mirror and a condenser lens must bealigned with a higher degree of accuracy. Especially when the distancebetween the projector and a screen must be longer with a highmagnification, the adjustment of the position of the light source with ahigher degree of accuracy is a very important factor for idealprojection.

However, the prior art devices for three-dimensional adjustment of alight source are generally complex in mechanism and operation, as wellas large in size and heavy in weight, so that they do not serve tominiaturize the projectors and the like.

SUMMARY OF THE INVENTION It is therefore an object of the presentinvention to provide a device for projectors and the like capable ofthree-dimensional adjustment of the position of a light source, whichdevice is compact in size, especially in thickness and simple inoperation.

The device for adjusting the position of a light source for projectorsin accordance with the present invention comprises a base detachablyattached to the projector frame, a main adjustment member which ismounted to the base by means adapted to adjust the vertical and angularposition of the main adjustment member relative to the base, anauxiliary adjustment member rotatably mounted to the main adjustmentmember and supporting a socket for a light source, and means to adjustthe angular position of the auxiliary adjustment BRIEF DESCRIPTION OFTHE DRAWING:

FIG. 1 is a side view of a device in accordance with the presentinvention; and

FIG. 2 is a bottom view thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring to FIGS. 1 and 2, a base 2 of, for example, a bayonet mounttype and having a center aperture 1a is detachably attached to a frame 1of an overhead projector. The base 2 is mounted by a pair of knobs 18for attachment to and detachment from the frame 1. One end of a lever 3is pivotably mounted on a shaft 4 to the base 2, and an upright pin 5extends from the other end of the lever 3.

A main adjustment member 6 is provided with a bent portion 6a U-shapedin cross section (See FIG. 1), a center aperture 6b, a bifurcatedportion 60 in diametrically opposed relation with the bent portion 6aand a pair of upright portions 6d extending from the free ends of thearms of the bifurcated portion 6c. The main adjustment member 6 isrotatably mounted on the base 2 by a threaded rod 7 extending throughthe bent portion 6a, and is also slidable along the axis of the threadedrod 7. A nut 19 threadably mounted on the threaded rod 7 is snuglyfitted into the space defined by the leg portions of the U-shaped bentportion 6a of the main adjustment member 6. A screw 20 is threadablyconnected through the pair of upright portions 6d, so that when thescrew 20 is tightened, the pin 5 fitted into the bifurcated portion 6dmay be clamped in position, whereby the rotation as well as the verticalmovement of the main adjustment member 6 may be positively prevented.

An auxiliary adjustment member 8 supporting the legs 12 of a socket 11for receiving a projecting lamp 17 such as an iodine lamp has its oneend rotatably connected to the main adjustment member 6 by a shaft 9 anda washer l0 and has a groove 8a formed in diametrically opposed relationwith the shaft 9 and adapted to receive therein a pin 15 extending fromoneend of an adjustment lever 13 whose other end is rotatably mounted bya shaft 14 to the main adjustment member An ellipsoidal reflector l6securely fixed to the frame 1 reflects the light beams from the lamp 17toward a projection lens (not shown).

Next the mode of operation will be described.

For the vertical adjustment of the light source 17, first the screw 20is loosened and then the nut 19 is rotated so that the main adjustmentmember 6 is caused to move vertically along the threaded rod 7 and thepin 5 to a desired position. Thereafter the screw 20 may be tightenedagain so that the main adjustment member 6 may be locked in the desiredposition.

For the adjustment of the position of the light source 17 in thedirection substantially perpendicular to the paper of FIG. 1, first thescrew 20 is loosened so that the main adjustment member 6 may be rotatedabout the threaded rod 7 by the lever 3 to a desired position.Thereafter, the screw 20 is tightened so that the main adjustment member6 may be securely locked in the desired angular position.

For the adjustment in the horizontal direction, that is the adjustmentto the right or left in FIG. 1, the adjustment lever 13 is rotated aboutits shaft 14 so that the auxiliary adjustment member 8 may be rotatedabout its shaft 9 to a desired position. In consequence, the lightsource 17 may be displaced to a desired position. In this case, thewasher 10 must have a suitable locking force in order to ensure that theauxiliary adjustment member 8 may be securely held in desired position.

The base 2, lever 3, main and auxiliary adjustment members 6 and 8 andadjustment lever 13 are all made of a metal and designed so flat thatthe device may become very compact in size, especially in thickness.

What is claimed is:

1. A device for adjusting the position of a light source adapted formounting on the frame of a projector comprising:

frame and having:

i. a first flat lever member pivoted at one end to said base member andhaving a first upstanding pin extending away from said base member onits opposite end; and

ii. a threaded rod fixed to said base member diametrically opposite saidfirst lever member and extending in the same direction as said firstupstanding pin;

b. a first flat adjustment member having a first aperture therein forreceiving said threaded rod and means thereon cooperating with saidthreaded rod and said first upstanding pin by which said firstadjustment member is mounted to said base member for adjustment of thespacing between said base member and said first adjustment member andfor adjustment in one angular direction in a plane parallel to that ofsaid base member; and

. a second flat adjustment member carrying the light source andpivotably mounted on said first flat adjustment member for adjusting theposition of the light source in another angular direction in a planeparallel to that of said base member by means ineluding:

i. a pivot on said first adjustment member; and

ii. a second flat lever member pivotally mounted on said firstadjustment member and having a second pin thereon extending into agroove in said second adjustment member.

2. A device as in claim 1 wherein said cooperating means on said firstflat adjustment member comprises:

i. a bent portion at an edge of said first adjustment member with anextension thereon having a second aperture therein disposed oppositesaid first aperture and for receiving said threaded rod;

ii. a nut member threadably mounted on said threaded rod between saidfirst and second apertures;

iii. a pair of arms extending from said first adjustment memberdiametrically opposite said bent portion for receiving said firstupstanding pin between them and having aperture means thereon forreceiving a screw member; and

iv. a screw member threadably mounted through said aperture means forreleasably clamping said first pin between said pair of arms.

1. A device for adjusting the position of a light source adapted formounting on the frame of a projector comprising: a. a flat base memberdetachably secured to said frame and having: i. a first flat levermember pivoted at one end to said base member and having a firstupstanding pin extending away from said base member on its opposite end;and ii. a threaded rod fixed to said base member diametrically oppositesaid first lever member and extending in the same direction as saidfirst upstanding pin; b. a first flat adjustment member having a firstaperture therein fOr receiving said threaded rod and means thereoncooperating with said threaded rod and said first upstanding pin bywhich said first adjustment member is mounted to said base member foradjustment of the spacing between said base member and said firstadjustment member and for adjustment in one angular direction in a planeparallel to that of said base member; and c. a second flat adjustmentmember carrying the light source and pivotably mounted on said firstflat adjustment member for adjusting the position of the light source inanother angular direction in a plane parallel to that of said basemember by means including: i. a pivot on said first adjustment member;and ii. a second flat lever member pivotally mounted on said firstadjustment member and having a second pin thereon extending into agroove in said second adjustment member.
 2. A device as in claim 1wherein said cooperating means on said first flat adjustment membercomprises: i. a bent portion at an edge of said first adjustment memberwith an extension thereon having a second aperture therein disposedopposite said first aperture and for receiving said threaded rod; ii. anut member threadably mounted on said threaded rod between said firstand second apertures; iii. a pair of arms extending from said firstadjustment member diametrically opposite said bent portion for receivingsaid first upstanding pin between them and having aperture means thereonfor receiving a screw member; and iv. a screw member threadably mountedthrough said aperture means for releasably clamping said first pinbetween said pair of arms.